RNA Sequences

Abstract

All RNA molecules have a primary structure which consists of a backbone of alternating ribose and phosphate residues with a purine (guanine or adenine) or pyrimidine (uracil or cytosine) base attached to each ribose (Fig. 1). Although these four bases (abbreviated as G, A, U and C respectively) predominate, some bases may be modified in the formation of the mature molecule. Also there is 2’-O-methylation of a few ribose residues. A comprehensive list of the structures of these modified residues and of the symbols used to denote them has been published (Dunn and Hall 1975).